ISO spectroscopic observations of Carina region Original Research Article

The Carina Nebula region (l ∼ 287° and b ∼ −0.6°) of about 20′ × 40′ has been observed by ISO/LWS with the spatial separation of 3′. Several emission lines, such as [OI] 63, 145μm, [OIII] 52, 88μm, [NIII] 57μm, [NII] 122μm and [CII] 157μm have been detected in the spectra of most observed positions. The LWS observations of the ionic lines indicate the presence of very low electron density gas (ne < 10 cm−3) extended over the Galactic plane in a scale of kpc unambiguously for the first time.